The reasons for adding white corundum powder to sandpaper, abrasive cloth, and abrasive belt slurry
1. Core principles
White corundum (α-Al2O3, Mohs hardness 9.0, pure white, low impurities, moderate self-sharpening, toughness better than silicon carbide, sharp edges and corners of particles, white color); emery cloth slurry refers to the base glue, cover glue, and sizing coating slurry for emery cloth sand planting. The abrasive is filled into the resin sizing and then solidifies to form the grinding surface of the emery cloth.
II. Main functions of adding white corundum to abrasive cloth, sandpaper, and abrasive belt slurry
1. Serving as the primary grinding aggregate (most important): White corundum has high toughness and is not easily broken, making it suitable for grinding stainless steel, carbon steel, alloy steel, aluminum alloy, and mold steel; black silicon carbide is suitable for hard and brittle materials (glass, ceramics, cast iron); white fused alumina is primarily used for polishing and grinding metal workpieces.
White corundum is the preferred filler for dry abrasive cloth, waterproof and water-resistant abrasive cloth, flexible abrasive cloth, and rolled abrasive belt slurry.
2. Increased Adhesive Layer Hardness and Wear Life: The resin base adhesive itself is relatively soft. Incorporating white corundum powder increases the hardness of the adhesive layer after curing, making the sand-coated adhesive less susceptible to wear and tear from metal, thus extending the lifespan of the sandpaper.
3. Improved Sand Adhesion and Prevention of Sand Particle Shedding: The addition of ultrafine white corundum powder to the sandpaper, abrasive cloth, and belt slurry increases the adhesive’s frictional bonding ability, locking in large sand particles and reducing sand shedding and particle loss after sanding.
4. Heat Dissipation and Resistance to High-Temperature Burning: Grinding friction generates heat. White corundum’s excellent high-temperature resistance helps dissipate grinding heat, preventing the sandpaper adhesive layer from softening, sticking, or burning at high temperatures.
5. Color Adjustment and Clean White Appearance: White corundum powder is pure white, allowing for the production of light-colored, high-grade polishing cloths, beauty sandpaper, and jewelry polishing belts, unlike black silicon carbide which can cause blackening.
6. Cost Reduction with Filler: Ultrafine white corundum micropowder is used as an inorganic filler to fill epoxy resin and phenolic resin slurries, reducing the amount of resin raw materials used and controlling production costs, while not significantly reducing the adhesive bonding strength.
III. Division of Applications of White Corundum in Abrasive Cloth, Sandpaper, and Abrasive Belt Slurries
180#-600# White corundum slurry aggregate and main abrasive material, used for rough grinding, rust removal, and weld seam grinding.
800#-2000# Ultrafine white corundum micropowder with adhesive filler, used for polishing abrasive cloth, flexible polishing belts, and mirror-finish abrasive paper slurry filler, for fine polishing of metal surfaces.
Submicron ultrafine white corundum micropowder 1500#-8000# High-end mirror-finish abrasive cloth, metallographic abrasive paper, and precision mold polishing abrasive belt slurry filler, resulting in a finely textured finished product.